From: Lai Jiangshan <laijs@cn.fujitsu.com>
To: Tejun Heo <tj@kernel.org>
Cc: <linux-kernel@vger.kernel.org>,
Andrew Morton <akpm@linux-foundation.org>,
Jean Delvare <jdelvare@suse.de>,
Monam Agarwal <monamagarwal123@gmail.com>,
Jeff Layton <jlayton@redhat.com>,
Andreas Gruenbacher <agruen@linbit.com>,
Stephen Hemminger <stephen@networkplumber.org>
Subject: Re: [PATCH 2/4] idr: reduce the number of MAX_IDR_FREE
Date: Wed, 23 Apr 2014 09:55:49 +0800 [thread overview]
Message-ID: <53571DA5.1010603@cn.fujitsu.com> (raw)
In-Reply-To: <20140422195821.GB2314@mtj.dyndns.org>
On 04/23/2014 03:58 AM, Tejun Heo wrote:
> On Tue, Apr 22, 2014 at 06:16:19PM +0800, Lai Jiangshan wrote:
>> +/*
>> + * Number of idr_layer structs to leave in free list.
>> + * When idr is not empty, we need atmost (MAX_IDR_LEVEL - 1) idr_layers
>> + * to build up and atmost (MAX_IDR_LEVEL - 1) idr_layers to allocate down.
>> + * When idr is empty need atmost MAX_IDR_LEVEL layers.
>> + */
>> +#define MAX_IDR_FREE max((MAX_IDR_LEVEL * 2 - 2), MAX_IDR_LEVEL)
>
> I don't know. Do we really wanna be this sophiscated about it when
> the cost of mistake would be an unexpected id allocation failure which
> would *EXTREMELY* difficult to track down or reproduce? Let's please
> keep it dumb and safe.
Do you mean "I need additional free layers to
hide any possible bugs"? let me nervous.
> With preloading we aren't even caching it
> per-idr. I don't think this is something we want to do.
Understood.
>
> Nacked-by: Tejun Heo <tj@kernel.org>
>
> Thanks.
>
next prev parent reply other threads:[~2014-04-23 1:52 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-04-22 10:16 [PATCH 0/4] idr: idr cleanups Lai Jiangshan
2014-04-22 10:16 ` [PATCH 1/4] idr: proper invalid argument handling Lai Jiangshan
2014-04-22 19:16 ` Andrew Morton
2014-04-22 19:46 ` Andrew Morton
2014-04-22 19:54 ` Tejun Heo
2014-04-22 10:16 ` [PATCH 2/4] idr: reduce the number of MAX_IDR_FREE Lai Jiangshan
2014-04-22 19:58 ` Tejun Heo
2014-04-23 1:55 ` Lai Jiangshan [this message]
2014-04-22 10:16 ` [PATCH 3/4] ida: in-place ida allocation Lai Jiangshan
2014-04-22 20:02 ` Tejun Heo
2014-04-23 1:44 ` Lai Jiangshan
2014-04-22 10:16 ` [PATCH 4/4] idr: reorder the fields Lai Jiangshan
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